FRANKFURT, Germany - Lufthansa knew that the co-pilot of the passenger plane that crashed in the French Alps last week had suffered from an episode of "severe depression" before he finished his flight training with the German airline.

FILE - In this Oct. 2, 2014 file photo, people pass a Wall Street subway stop, in New York's Financial District. U.S. stocks moved lower in early trading Tuesday, March 31, 2015, erasing some gains from the day before.